var GPS = {
	PI: 3.14159265358979324,
	x_pi: 3.14159265358979324 * 3000.0 / 180.0,
	delta: function(lat, lon) {
		// Krasovsky 1940
		//
		// a = 6378245.0, 1/f = 298.3
		// b = a * (1 - f)
		// ee = (a^2 - b^2) / a^2;
		var a = 6378245.0; //  a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
		var ee = 0.00669342162296594323; //  ee: 椭球的偏心率。
		var dLat = this.transformLat(lon - 105.0, lat - 35.0);
		var dLon = this.transformLon(lon - 105.0, lat - 35.0);
		var radLat = lat / 180.0 * this.PI;
		var magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		var sqrtMagic = Math.sqrt(magic);
		dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * this.PI);
		dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI);
		return {
			'lat': dLat,
			'lon': dLon
		};
	},

	baiduTomars: function(lat, lon) {
		var mars_point = {
			lon: 0,
			lat: 0
		};
		var x = lon - 0.0065;
		var y = lat - 0.006;
		var z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * this.x_pi);
		var theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * this.x_pi);
		mars_point.lon = z * Math.cos(theta);
		mars_point.lat = z * Math.sin(theta);


		return mars_point;
	},
	//WGS-84 to GCJ-02
	gcj_encrypt: function(wgsLat, wgsLon) {
		if (this.outOfChina(wgsLat, wgsLon))
			return {
				'lat': wgsLat,
				'lon': wgsLon
			};

		var d = this.delta(wgsLat, wgsLon);
		return {
			'lat': wgsLat + d.lat,
			'lon': wgsLon + d.lon
		};
	},
	//GCJ-02 to WGS-84
	gcj_decrypt: function(gcjLat, gcjLon) {
		if (this.outOfChina(gcjLat, gcjLon))
			return {
				'lat': gcjLat,
				'lon': gcjLon
			};

		var d = this.delta(gcjLat, gcjLon);
		return {
			'lat': gcjLat - d.lat,
			'lon': gcjLon - d.lon
		};
	},
	//GCJ-02 to WGS-84 exactly
	gcj_decrypt_exact: function(gcjLat, gcjLon) {
		var initDelta = 0.01;
		var threshold = 0.000000001;
		var dLat = initDelta,
			dLon = initDelta;
		var mLat = gcjLat - dLat,
			mLon = gcjLon - dLon;
		var pLat = gcjLat + dLat,
			pLon = gcjLon + dLon;
		var wgsLat, wgsLon, i = 0;
		while (1) {
			wgsLat = (mLat + pLat) / 2;
			wgsLon = (mLon + pLon) / 2;
			var tmp = this.gcj_encrypt(wgsLat, wgsLon)
			dLat = tmp.lat - gcjLat;
			dLon = tmp.lon - gcjLon;
			if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold))
				break;

			if (dLat > 0) pLat = wgsLat;
			else mLat = wgsLat;
			if (dLon > 0) pLon = wgsLon;
			else mLon = wgsLon;

			if (++i > 10000) break;
		}
		//console.log(i);
		return {
			'lat': wgsLat,
			'lon': wgsLon
		};
	},
	//GCJ-02 to BD-09
	bd_encrypt: function(gcjLat, gcjLon) {
		var x = gcjLon,
			y = gcjLat;
		var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * this.x_pi);
		var theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * this.x_pi);
		bdLon = z * Math.cos(theta) + 0.0065;
		bdLat = z * Math.sin(theta) + 0.006;
		return {
			'lat': bdLat,
			'lon': bdLon
		};
	},
	//BD-09 to GCJ-02
	bd_decrypt: function(bdLat, bdLon) {
		var x = bdLon - 0.0065,
			y = bdLat - 0.006;
		var z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * this.x_pi);
		var theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * this.x_pi);
		var gcjLon = z * Math.cos(theta);
		var gcjLat = z * Math.sin(theta);
		return {
			'lat': gcjLat,
			'lon': gcjLon
		};
	},
	//WGS-84 to Web mercator
	//mercatorLat -> y mercatorLon -> x
	mercator_encrypt: function(wgsLat, wgsLon) {
		var x = wgsLon * 20037508.34 / 180.;
		var y = Math.log(Math.tan((90. + wgsLat) * this.PI / 360.)) / (this.PI / 180.);
		y = y * 20037508.34 / 180.;
		return {
			'lat': y,
			'lon': x
		};
		/*
		 if ((Math.abs(wgsLon) > 180 || Math.abs(wgsLat) > 90))
		 return null;
		 var x = 6378137.0 * wgsLon * 0.017453292519943295;
		 var a = wgsLat * 0.017453292519943295;
		 var y = 3189068.5 * Math.log((1.0 + Math.sin(a)) / (1.0 - Math.sin(a)));
		 return {'lat' : y, 'lon' : x};
		 //*/
	},
	// Web mercator to WGS-84
	// mercatorLat -> y mercatorLon -> x
	mercator_decrypt: function(mercatorLat, mercatorLon) {
		var x = mercatorLon / 20037508.34 * 180.;
		var y = mercatorLat / 20037508.34 * 180.;
		y = 180 / this.PI * (2 * Math.atan(Math.exp(y * this.PI / 180.)) - this.PI / 2);
		return {
			'lat': y,
			'lon': x
		};
		/*
		 if (Math.abs(mercatorLon) < 180 && Math.abs(mercatorLat) < 90)
		 return null;
		 if ((Math.abs(mercatorLon) > 20037508.3427892) || (Math.abs(mercatorLat) > 20037508.3427892))
		 return null;
		 var a = mercatorLon / 6378137.0 * 57.295779513082323;
		 var x = a - (Math.floor(((a + 180.0) / 360.0)) * 360.0);
		 var y = (1.5707963267948966 - (2.0 * Math.atan(Math.exp((-1.0 * mercatorLat) / 6378137.0)))) * 57.295779513082323;
		 return {'lat' : y, 'lon' : x};
		 //*/
	},
	// two point's distance
	distance: function(latA, lonA, latB, lonB) {
		var earthR = 6371000.;
		var x = Math.cos(latA * this.PI / 180.) * Math.cos(latB * this.PI / 180.) * Math.cos((lonA - lonB) *
			this.PI / 180);
		var y = Math.sin(latA * this.PI / 180.) * Math.sin(latB * this.PI / 180.);
		var s = x + y;
		if (s > 1) s = 1;
		if (s < -1) s = -1;
		var alpha = Math.acos(s);
		var distance = alpha * earthR;
		return distance;
	},
	outOfChina: function(lat, lon) {
		if (lon < 72.004 || lon > 137.8347)
			return true;
		if (lat < 0.8293 || lat > 55.8271)
			return true;
		return false;
	},
	transformLat: function(x, y) {
		var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0;
		ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0;
		return ret;
	},
	transformLon: function(x, y) {
		var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0;
		ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0;
		return ret;
	},
	/** * 获取两个经纬度之间的距离 * @param lat1 第一点的纬度 * @param lng1 第一点的经度 * @param lat2 第二点的纬度 * @param lng2 第二点的经度 * @returns {Number} */
	getDistance: function(
		lat1, lng1, lat2, lng2) {
		var f = getRad((lat1 + lat2) / 2);
		var g = getRad((lat1 - lat2) / 2);
		var l = getRad((lng1 - lng2) / 2);
		var sg = Math.sin(g);
		var sl = Math.sin(l);
		var sf = Math.sin(f);
		var s, c, w, r, d, h1, h2;
		var a = 6378137.0; //The Radius of eath in meter. 
		var fl = 1 / 298.257;
		sg = sg * sg;
		sl = sl * sl;
		sf = sf * sf;
		s = sg * (1 - sl) + (1 - sf) * sl;
		c = (1 - sg) * (1 - sl) + sf * sl;
		w = Math.atan(Math.sqrt(s / c));
		r = Math.sqrt(s * c) / w;
		d = 2 * w * a;
		h1 = (3 * r - 1) / 2 / c;
		h2 = (3 * r + 1) / 2 / s;
		s = d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg));
		s = s / 1000;
		s = s.toFixed(2); //指定小数点后的位数。 
		return s;
	}

};

function getRad(d) {
	var PI = Math.PI;
	return d * PI / 180.0;
}

function getShortDistancePianqu(pianquList, location) {

	var a = {
		"baseName": "",
		"baseId": "",
		"pianquName": "",
		"pianquId": "",
		"distance": 10000
	}
	//便利基地
	for (var i = 0; i < pianquList.length; i++) {
		var tempBase = pianquList[i].base;

		if (pianquList[i].areaGrouplist != undefined) {
			//遍历片区
			for (var j = 0; j < pianquList[i].areaGrouplist.length; j++) {
				var pianqu = pianquList[i].areaGrouplist[j];
				var distance = getDistance(Number(location[1]), Number(location[0]), pianquList[i].areaGrouplist[j].lat,
					pianquList[
						i].areaGrouplist[j].lng);
				console.log("距离 ====================" + distance + " name == " + pianquList[i].areaGrouplist[j].agName);
				//找出距离最小的一个
				if (distance < a.distance) {
					a.baseName = tempBase.baseName;
					a.baseId = tempBase.baseId;
					a.pianquName = pianquList[i].areaGrouplist[j].agName;
					a.pianquId = pianquList[i].areaGrouplist[j].agId;
					a.distance = distance;
					console.log("片区信息" + JSON.stringify(a));
				}
			}
		}

	}
	console.log("最近的片区信息" + JSON.stringify(a));
	return a;

}

function getDistance(lat1, lng1, lat2, lng2) {
	var f = getRad((lat1 + lat2) / 2);
	var g = getRad((lat1 - lat2) / 2);
	var l = getRad((lng1 - lng2) / 2);
	var sg = Math.sin(g);
	var sl = Math.sin(l);
	var sf = Math.sin(f);
	var s, c, w, r, d, h1, h2;
	var a = 6378137.0; //The Radius of eath in meter. 
	var fl = 1 / 298.257;
	sg = sg * sg;
	sl = sl * sl;
	sf = sf * sf;
	s = sg * (1 - sl) + (1 - sf) * sl;
	c = (1 - sg) * (1 - sl) + sf * sl;
	w = Math.atan(Math.sqrt(s / c));
	r = Math.sqrt(s * c) / w;
	d = 2 * w * a;
	h1 = (3 * r - 1) / 2 / c;
	h2 = (3 * r + 1) / 2 / s;
	s = d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg));
	s = s / 1000;
	//s = s.toFixed(2); //指定小数点后的位数。 
	return s;
}
if (typeof module === "object" && typeof module.exports === "object") {
	module.exports = GPS;
	//export default//建议使用nodejs的module导出方式，如报错请使用export方式导出
}
